Tue, 09 Jun 2026 10:50:00 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170343#Comment_170343 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170343#Comment_170343 Fri, 15 Mar 2013 14:45:30 +0000 Pile-o-Stone
I wonder if anyone has fitted these before and can help me. For some reason I have it in my head that I have to put lime plaster on the rear of the boards before attaching them to the wall with mechanical fixings (a bit like an adhesive you'd put on the back of a ceramic tile).

Reading the blurb on the Pavadentro instruction, it seems that you apply a levelling plaster onto the wall, let it dry and then just attach the Pavadentro dry onto the wall with the mechanical fixings. This wouldbe a a lot more straightforward, but I want to make sure I'm doing it right before I make a start!

Help!! :)]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170346#Comment_170346 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170346#Comment_170346 Fri, 15 Mar 2013 15:04:44 +0000 Beau .http://www.mikewye.co.uk/NBT_Technical_Manual_PAVADENTRO.pdf]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170347#Comment_170347 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170347#Comment_170347 Fri, 15 Mar 2013 15:24:50 +0000 Pile-o-Stone Posted By: BeauThese are probably the same instructions but if not they could help.
.http://www.mikewye.co.uk/NBT_Technical_Manual_PAVADENTRO.pdf" rel="nofollow" >http://www.mikewye.co.uk/NBT_Technical_Manual_PAVADENTRO.pdf

Hi, yes, that's the instruction sheet I was looking at. I think when I originally read it I saw the following:

"1. Absorbent plaster: It is recommended to apply a capillary conductive absorbent plaster across the whole surface
between existing wall and wood fibre insulation board.

Pure mineral plasters are ideal for this as they have capillary
conductive properties. Suitable materials are clay and lime
plaster systems. These plasters should contain no cement
or minimum amounts of cement if possible. The following
plasters are suitable for example:
• As levelling coat ≤ 5 mm use BaumitBayosan RK 70 N
• As levelling coat ≥ 5 mm use BaumitBayosan RK 38
• Clay plasters from Claytec

Apply a level coat on existing construction element and
let dry."

and missed the 'let it dry' bit and just assumed that the Absorbent layer between the wall and the insulation board was like adhesive, rather than a dry levelling coat.

After re-reading the instructions for them umpteenth time, I think that the boards do literally just go dry onto the (now) flat wall. I hope so as this means that it's a much quicker and cleaner job.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170358#Comment_170358 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170358#Comment_170358 Fri, 15 Mar 2013 16:08:21 +0000 jamesingram levelling coat only if necessary , ie. if wall uneven by >8mm (quite likely in most cases I'd have thought)
Then apply Absorbent plasterer to board with serated trowel , tap on to wall til level then mechanicial fix.
I asked the question regarding straight mechanicial fitting to levelling coat. They used to do this but now advise
the trowel on to board + mechanicial method.
Might be worth calling to check though.
Perhaps if you went with a deeper toothed trowel with the RK70N you could get away without the levelling coat ??]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170361#Comment_170361 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170361#Comment_170361 Fri, 15 Mar 2013 16:19:27 +0000 Nick Parsons
From the Pavadentro manual:

1. NBT levelling plaster: If the existing wall has unevenesses
greater than 8 mm a levelling coat has to be applied.
This levelling plaster has to be capillary conductive. Allow
1 day per 1 mm thickness drying time for the levelling coat
before applying the absorbent plaster and the NBT PAVADENTRO
boards. NBT recommands using the following
lime plaster:
• As levelling coat use NBT lime plaster RK 38

2. NBT absorbent plaster: It is essential to apply a capillary
conductive absorbent plaster across the whole surface
between existing wall and NBT PAVADENTRO insulation
board. The NBT absorbent plaster can either be applied to
the wall or the boards surface as an adhesive bond. This
should be at least 8 mm thick and applied with a toothed
trowel.

2 is the adhesive layer. There's only 3 mech fixings per board, so the prime fixing has to be the adhesive.

Nick]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170375#Comment_170375 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10312&Focus=170375#Comment_170375 Fri, 15 Mar 2013 18:26:54 +0000 Pile-o-Stone
It makes a lot more sense to have the absorbant layer not just as an adhesive, but also as a capillary conductor for any moisture in the wall.

I checked out the instructions on the Mike Wye and Ty-Mawr websites and they don't have the instructions about using lime as an adhesive, they are both saying that you attach the boards to the dry, levelled wall (with 4 fixings). After googling the words "2. NBT absorbent plaster: It is essential to apply " I found the following link:

http://www.natural-building.co.uk/systems/renovation/pavadentro

Thanks again. :)]]>